package com.yixiu.study.juc.collection;


import java.util.Map;
import java.util.UUID;
import java.util.concurrent.ConcurrentHashMap;

/**
 * @CalssName T03_SyncHashMap
 * @Description
 * @Author yixiu
 * @Date 2021/6/28 11:06
 * @Verison 1.0
 **/
public class T04_ConcurrentHashMap {

    static Map<UUID, UUID> m = new ConcurrentHashMap<>();
    static int count = Constants.COUNT;
    static UUID[] keys = new UUID[count];
    static UUID[] values = new UUID[count];
    static final int THREAD_COUNT = Constants.THREAD_COUNT;

    static {
        for (int i = 0; i < count; i++) {
            keys[i] = UUID.randomUUID();
            values[i] = UUID.randomUUID();
        }
    }

    static class MyThread extends Thread{
        int start;
        int gap = count/THREAD_COUNT;

        public MyThread(int start){
            this.start = start;
        }

        @Override
        public void run(){
            for (int i = start; i < start+gap; i++) {
                m.put(keys[i], values[i]);
            }

        }
    }

    public static void main(String[] args) {
        long start = System.currentTimeMillis();
        Thread[] threads = new Thread[THREAD_COUNT];

        for (int i = 0; i < threads.length; i++) {
            threads[i] = new MyThread(i * (count/THREAD_COUNT));
        }

        for(Thread t : threads){
            t.start();
        }

        for(Thread t : threads){
            try {
                t.join();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }

        long end = System.currentTimeMillis();
        System.out.println(end - start);

        System.out.println(m.size());

        //-----------------------------------

        start = System.currentTimeMillis();
        for (int i = 0; i < threads.length; i++) {
            threads[i] = new Thread(() -> {
                for (int j = 0; j < 1000000; j++) {
                    m.get(keys[10]);
                }
            });
        }

        for(Thread t : threads){
            t.start();
        }

        for(Thread t : threads){
            try {
                t.join();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }


        end = System.currentTimeMillis();
        System.out.println(end - start);

        System.out.println(m.size());
    }


}
